"The Oceano sand dune area is recognized by scientists, conservationists, government agencies, and the public as the finest, most extensive coastal dunes remaining in California. Most of the material that forms these dunes has ocean currents, and then shaped by the wind into the dunes that we see today.

The prevailing winds that blow in from the ocean push sand particles up into wave-like crests that run north-south. On the west or windward side the slope is gentle. On the east or leeward side the slope is quite steep. Sand grains, as they are blown over the dune crest tend to accumulate high on the leeward slope; then, periodically thin tongues of sand slide down. For this reason the leeward slope is called a "slipface.""